Connecting-circuit for telephone switching systems.



H. P CLAUSEN; CONNECTING CIRCUIT FOR TELEPHONE SWITCHING SYSTEMS,

APFUCATIGH FILED AUG-27, !9l5.

Patented Apr. 10, 1917.

m wwm mye/vlon fienry f? (Sm/sen. W Q

1d A W l V/fnes entrain HENRY P. CLAUSEN, OF MOUNT VERNCIN, NEW YORK, ASSIGNOE, BY IVICESNE ASSIGN- MENTS, T0 WESTERN ELECTRIC GQMPANY, INGURPOEATED, CQREOBATION OF NEW YORK.

CONNECTING-CIRCUIT FOR TELEPHONE SWITCHING SYSTEMS.

Application filed August 27, 1915.

To all whom it may concern: 1

Be it known that I, Hurray P. CLAUSEN, a citizen of the United States, residing at Mount Vernon, in the county of VVestchcster and State of New York, have invented certain new and useful Improvements in Connecting-Circuits for Telephone Switching Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to connecting cir cuits for telephone switching systems of the manual type, and has for its object to pro 'vide means for assisting the operator in the supervision and control of such circuits.

In accordance with the general features of this invention, means are provided for giving the operator a warning signal in case of a premature disconnection of either end of a connecting circuit. The warning signal may be in the form of a tone in the operators telephone set. The tone-may be given to the operator through the operation of the usual supervisory relays which are associated with the ordinary connecting circuit, the only additional apparatus for carrying out this invention being the tone producing mechanism.

The accompanying drawing illustrates one of the organizations by which this invention may be eflectuated.

In the drawing, subscribers lines A and B are each connected by means of line wires 1 and 2 to a line jack 3 located at a central office. Included in each of these line circuits is the customary line relay 4: controlling line lamp 5 and a cut-off relay 6. At the central ofiice there is provided'an operators cord circuit terminating in connecting plugs 7 and 11. Included in the talking strands of each end of the cord circuit are the customary supervisory relays 8, 9 and 12, 13, the former of which conjointly controls the'supervisory lamp 10, and the latter the supervisory lamp 14. Associated with the cord circuit is a circuit interrupting device 15 under the control of the operator by having its circuit include contacts of her listening key. The interrupting device 15 is adapted to produce a tone in the operators head set when a circuit therefor is established. The actuation of either pair of the supervisory relays when the other pair is dee'nergized eflects the closure of a circuit individual to a given pair of said relays for Specification of Letters Patent.

Patented Apr. 141, 1917.

Serial No. 47,675.

the actuation of the interrupter 15. Ring ing current may be applied to a called line by means of a ringing key 28.

The operation of the apparatus in the drawing may best be understood by assuming that the subscribers lines A and B have been connected by means of the cord circuit. In such an event the supervisory relays 8 and 9 will have been energized over the following path: battery, coil of relay 8, ring strand of the plug 7 and jack 3 respectively, line wire 1, through the substation A, back over line wire 2, tip strand of the jack 3 and plug 7 respectively, coil of relay 9, to ground. Likewise the energization of the supervisory relays 12 and 13 will have been effected over the circuit which may be traced as follows: battery, coil of relay 12, ring strand and the plug 11 and jack 3 respectively, line wire 1, through substation B, back over line wire 2, tip strand of the jack 3 and plug 11 respectively, coil of relay 13, to ground. If the operator should inadvertently withdraw either of the plugs 7 or 11 from the jack associated with subscriber A. or B, one pair or the other of the supervisory relays will be deenergized. We may assume that the operator prematurely with drew the answering plug 7. In this instance the supervisory relays 8, 9 will have been deenergized, while the supervisory relays 12, 13 will have been maintained energized. Under these conditions a circuit for the in terrupter 15 will have been established over the following path: battery, interrupter 15, contact 16 of the operators listening key, conductors 17, 18, contact 19, conductor 20, contact 21, conductor 22, contact 23, conductor 24, contact 25, conductor 26, winding of induction coil 27, to ground. The operation of the interrupter 15 will produce a warning tone or signal in the operators head set and indicate to her that the withdrawing oi the plug 7 was inopportune. This signal being given the instant she withdrew the plug 7, in many cases she may have an opportunity of instantly reinserting the plug 7 in the ack of the calling subscribers line, thus not seriously interrupting the conversation between subscribers A and B.

Now if we assume that the operator with drew the calling plug 11 instead of the answering plug 7, the supervisory relays 12 and 13 would have been deenergized in this 11 from the jack of .a busy line, and she can accordingly take any steps necessary to reestablish conversation between subscribers A and. B.

From the above it will be seenthat by the means contemplated by this invention, an

operator will be given a warning signal whenever she prematurely disconnects either one of the connecting plugs of her connecting circuit from a busy line. Upon receiving this signal she will be able in many cases to reestablish the connection she inadvertently disturbed, without seriously discommoding .or interrupting the conversing subscribers.

hat is claimed is:

1. A telephone system comprising a pair of subscribers lines terminating at a central office, a cord circuit connecting the lines together, a signaling device for the cord circuit, and an operating circuit for the signaling device controlled over one connected subscribers line and completed by the disconnection of the cord circuit from the other line.

2. A telephone system comprising two telephone lines, a link circuit connecting the lines together, a signaling device for the link circuit, and an operating circuit for the signaling device controlled over one connected line and completed by the disconnection of the link circuit from the other line.

3. Atelephone system comprising two subscribers lines, a cord circuit connecting the lines together, a relay for each end of the cord circuit energized over the respective connected subscribers lines, a tone producing device, and an energizing circuit for said device containing contacts of the relays.

4:. A telephone system comprising two telephone lines, a link circuit connecting the lines together, a tone producing device for the link circuit, and an energizing circuit for the tone producing device controlled over one connected line and completed by the disconnection of the link circuit from the other line.

5. A telephone system comprising two telephone lines, a link circuit connecting the lines together, a relay for each end of the link circuit energized over the respective connected lines, a tone producing device, and an energizing circuit for said device containing contacts of the relays.

6. In a telephone system, a pair of subscriberslines terminating in line jacks at a central oilice, a cord circuit :for connecting said lines together, a pairot' supervisory relays for each end ot said cord circuit, a tone producing device, and a plurality of energizing circuits for said device, the closure of a given one ot said circuits being conditioned upon the energization of one pair of said relays and the deenergization of the other pair of said relays.

7. In a telephone system, a pair of subscribers lines terminating in line jacks at a central o'liice, a cord circuit for connecting said lines togetheig-a pair of supervisory relays for each end of said cord-circuit, atone producing device, and a plurality of energizing circuits for said device, the closure of said circuits being controlled jointly by said relays acting in pairs.

8. In a telephone system, a pair of subscribers lines terminating in line jacks at a central ofiice, a cord circuit for connecting said lines together, a pair of supervisory relays for each end of said cord circuit, atone producing device, and a plurality of energizing circuits for said device, said circuits being controlled collectively by said relays, one of said circuitsbeing completed uponthe premature withdrawal of one of the connecting plugs of said cord circuit, whereby the operator will be given a tone notifying .her

of said withdrawal.

In witness whereof, I hereunto subscribe my name this 18th day of August A. 1).,

1915. HENRY P. CLAUSEN.

Copies of this patent maybe obtained for five cents each, by addressing the Commissioner of Batents, W ashing'ton, D. G. 

